The present invention relates to an apparatus which can be used to install add-on boards in a personal computer ("PC"). In particular, the present invention relates to an apparatus which is particularly well adapted for adding boards to PCs used in industrial environments, such as a rack-mounted PCs.
In industrial environments, it is common to have rack-mounted equipment. Such equipment typically includes a card receiving mechanism which permits boards to be slid directly into a rack-mounting cage adapted to receive and properly seat such cards, so that they achieve proper mechanical and electrical contact. There are presently a variety of standards which are used for rack-mounting equipment and cards associated with such equipment.
A problem which exists, however, is that since 1981, when IBM introduced its first PC which had an open architecture, the PC has been a catalyst for numerous manufacturers to produce a huge variety of add-on boards which are compatible with the PC architecture and software. While it would be virtually impossible to list the types of add-on boards which are presently available, they include memory boards, I/O boards, analog-to-digital converters, digital-to-analog converters, boards for interfacing a variety of displays, boards for interfacing a variety of serial and parallel devices, boards for interfacing a variety of disk drives, tape drives, CD-ROMs, etc.
In view of the availability of such a wide variety of add-on boards, and in view of the numerous languages, applications, and operating systems available for use on PCs, their use in both business and industrial environments is common and desirable. A problem with PC designs, though, has always been that the add-on or plug-in cards which are designed to be plugged into bus connectors on a PC's motherboard, were not designed from the beginning to be compatible with rack-mounted equipment. In particular, the PC plug-in cards which are commonly used are designed to be slid vertically downward into a bus connector located in a slot on the PC's motherboard, while the actual motherboard has a horizontal orientation.
The installation of an add-on board to a PC is typically accomplished by first removing the cover from the PC. This is usually accomplished by first removing screws from the rear of the PC which attach the cover to the PC's chassis. With the cover removed, a metal slot cover which is associated with an available slot is removed by first removing a screw which holds it in place, thereby exposing a vertically oriented opening at the rear of the PC's chassis. Then, an edge connector on the add-on board is inserted into a card edge connector (or "PC bus connector") which faces up from the motherboard. The act of inserting the edge connector of the add-on board into the card edge connector simultaneously places any external connectors, which are on the rear edge of the add-on board, through the (now exposed) slot opening on the rear of the chassis which is associated with that motherboard slot. Then, the screw which was removed to free the metal slot cover is replaced, thereby securing the add-on board in position. Next, the cover is replaced on the chassis, and it is screwed back into place. Finally, any cables which must be connected to any external connector on the rear edge of the add-on board (which extends through the PC's chassis), are connected, and the PC is returned to service.
In view of the possibility of dropping a screw when removing the slot cover, or when installing the add-on board, virtually all manufacturers of add-on boards advise the installer to remove power from the PC prior to performing any of the foregoing steps.
While the foregoing procedure is commonly done on desktop PCs, it is a difficult procedure to implement in a rack-mounted PC, of the type used in industrial applications, as it requires sufficient vertical space above the rack slot for the add-on card to be appropriately positioned for insertion into the PC bus connector, and for the removal and reinstallation of the slot cover screw.
A further problem with the installation of add-on cards in rack-mounted PCs is that any required external connectors, such as RS-232 connectors, have to be plugged into the appropriate connector on the PC card faceplate after the add-on board has been installed in the PC, the PC cover has been reinstalled on the chassis, and the PC has been reinstalled in the rack-mount, as required for appropriate electromagnetic interference ("EMI") protection.
Yet another problem with the procedure described, is that it is sometimes desirable to be able to add or remove add-on boards without first removing power from the PC. As set forth above, due to the possibility of dropping the slot cover screw, this procedure, if performed on a "hot" chassis, can be extremely dangerous to the PC.